From Wikipedia:
Outside of established traditions, particularly in the avant-garde, writers have produced a variety of work under more severe constraints; this is often what the term “constrained writing” is specifically applied to. For example:
- Reverse-lipograms: each word must contain a particular letter.
- Univocalic poetry, using only one vowel.
- Mandated vocabulary, where the writer must include specific words (for example, Quadrivial Quandary solicits individual sentences containing all four words in a daily selection).
- Bilingual homophonous poetry, where the poem makes sense in two different languages at the same time, constituting two simultaneous homophonous poems.
- Alliteratives or tautograms, in which every word must start with the same letter (or subset of letters; see Alphabetical Africa).
- Lipogram: a letter (commonly e or o) is outlawed.
- Acrostics: first letter of each word/sentence/paragraph forms a word or sentence.
- Abecedarius: first letter of each word/verse/section goes through the alphabet.
- Palindromes, such as the word “radar”, read the same forwards and backwards.
- Anglish, favouring Anglo-Saxon words over Greek and Roman/Latin words.
- Pilish, where the lengths of consecutive words match the digits of the number p.
- Anagrams, words or sentences formed by rearranging the letters of another.
- Limitations in punctuation, such as Peter Carey’s book True History of the Kelly Gang, which features no commas.
- One syllable article, a form unique to Chinese literature, using many characters all of which are homophones; the result looks sensible as writing but is very confusing when read aloud.
- Chaterism, where the length of words in a phrase or sentence increases or decreases in a uniform, mathematical way.
- Aleatory, where the reader supplies a random input.
- Erasure, which involves erasing words from an existing text and framing the result on the page as a poem.
The Oulipo group is a gathering of writers who use such techniques. The Outrapo group uses theatrical constraints.
There are a number of constrained writing forms that are restricted by length, including:
- Six-Word Memoirs: 6 words
- Haiku: ~ 3 lines (5–7–5 syllables or 2–3–2 beats recommended.)
- Minisaga: 50 words, +15 for title
- Drabble: 100 words
- Twiction: espoused as a specifically constrained form of microfiction where a story or poem is exactly 140 characters long.
- Sijo: three lines average 14–16 syllables, for a total of 44–46: theme (3, 4,4,4); elaboration (3,4,4,4); counter-theme (3,5) and completion (4,3).